This invention relates to a switching module and more particularly to a switching module for a solid-state keyboard.
In mechanical switching modules conventionally used in calculator keyboards or the like, single-pole, single-throw (SPST) momentary switches are utilized as keyboard switches. In the event the mechanical switch contacts of these switches do not make good electrical contact with one another when the switch is closed, no signal will be generated for effecting operation of the calculator. It has been found that under some operating conditions, dust particles between the contacts or other contaminants, such as an oxide coating on the contacts, may prevent them from closing a circuit. Thus, even though the keyboard pushbutton is properly depressed, a desired signal may not be generated and the calculator may fail to function properly.